Almera Auto weird fuel economy - shamus
I have a Nissan Almera 1.6 SLX Auto, 1997 model. The car is great all round.

However, the fuel economy, even for an auto, is weird. Can someone please shed some light ....

On motorway (or on a run) the car is remarkably economical, doing 40+mpg. However, around town it only does about 15mpg. I have checked by refilling and recalculating several times. Around town you can virtually see the fuel gauge drop.

The car's engine and gearbox are silky smooth. No hesitation, pinking, stalling etc. It has 50k miles with full Nissan History. The cat was ok during its last MOT a month or so ago.

Anyone got any ideas or similar circumstances. I would expect 25-30mpg around town - the car is driven VERY gently indeed.

Thanks !
Almera Auto weird fuel economy - Gen
I recently mended a friend's car (don't take it to the garage, I'll be done in half an hour I say, yeah right) which was leaking fuel out of the fuel return pipe to the tank. This seemed to mean that when idling a stream of petrol came out, but on longer run seemed okay fuel economy as not so much unused fuel to return. Pig of a 4job though, on two axle stands and had to drop the fuel tank a bit on a jack, though the piping only cost 4.99£.

So I would guess a return pipe fuel leak would show okay economy on high speed but bad around town. Stick your head under and look for a drip when its ticking over. Don't touch the exhaust when looking though like I did.

I could be 100% wrong though, just something I saw recently.
Almera Auto weird fuel economy - sean
The 40mpg on a run is probably explained by a lock-up pawl in the auto gearbox. It cuts out the torque converter so you're not wasting power through fluid losses.

I'd have thought 15mpg was sign of a definite fault around town.

It's tall, but air resistance won't be large at town speeds.

What gear is it in? Can your hear it change up?

What about the previous owner? Ask him.

Was there an owner before him? Same again.

You'll sort it, mate. Don't worry.
Almera Auto weird fuel economy - Gen
I assumed it suddenly has become much worse, but if always like this obviously my above post is offmark!
Almera Auto weird fuel economy - shamus
This is my 2nd Almera auto. Previous one averaged about 30-35mpg all round.

Around town, the gearbox is working and does go into top gear and I can the revs are very low from the rev counter.

Is it worth taking it to Nissan. They want £40+vat to put it on the test machine. Or is it better to use Home/Crypton tune ... although I doubt there is anything to adjust ...

I'll check for petrol leaks later today .. although never smelt any fumes.

Thanks !
Almera Auto weird fuel economy - Gen
If you don't smell it unlikely. One I saw smelt like a petrol station.

Almera Auto weird fuel economy - Aprilia
Does indeed sound odd. My Nissan QX 2.0 auto (big heavy body)does around 23-25mpg crawling around town and hits 32+ on the open road.

These are the possibilities, I think:

1. Transmission is not shifting up at the right time. Assuming it is the RL4F03 transmission then the data I have suggests upshifts at the following speeds on 25% throttle (i.e. light throttle).
1-2 @ 8mph
2-3 @ 18mph
3-4 @ 28mph
4-lockup @ 58mph

2. Brakes binding

3. Running rich (check to see if lambda about 1)

4. Fuel leakage


There can't be anything else.
Almera Auto weird fuel economy - Gen
If the brakes are binding careful touching around that area after 10 miles of little braking driving will let you know. And often a smell.

Might be worth jacking up and spinning wheels to see if spin freely. Remember handbrake off for back ones.
 

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